[gradle] How to download dependencies in gradle

I have a custom compile task.

task compileSpeedTest(type: JavaCompile) {
    classpath = files('build')
    source = fileTree('src/test/java/speed')
    destinationDir = file('bin')
}

Gradle doesn't try to download dependencies before its execution. I cannot find anywhere a task name which does it to add it on list dependsOn.

This question is related to gradle

The answer is


There is no task to download dependencies; they are downloaded on demand. To learn how to manage dependencies with Gradle, see "Chapter 8. Dependency Management Basics" in the Gradle User Guide.


This version builds on Robert Elliot's, but I'm not 100% sure of its efficacy.

// There are a few dependencies added by one of the Scala plugins that this cannot reach.
task downloadDependencies {
  description "Pre-downloads *most* dependencies"
  doLast {
    configurations.getAsMap().each { name, config ->
      println "Retrieving dependencies for $name"
      try {
        config.files
      } catch (e) {
        project.logger.info e.message // some cannot be resolved, silentlyish skip them
      }
    }
  }
}

I tried putting it into configuration instead of action (by removing doLast) and it broke zinc. I worked around it, but the end result was the same with or without. So, I left it as an explicit state. It seems to work enough to reduce the dependencies that have to be downloaded later, but not eliminate them in my case. I think one of the Scala plugins adds dependencies later.


It is hard to figure out exactly what you are trying to do from the question. I'll take a guess and say that you want to add an extra compile task in addition to those provided out of the box by the java plugin.

The easiest way to do this is probably to specify a new sourceSet called 'speedTest'. This will generate a configuration called 'speedTest' which you can use to specify your dependencies within a dependencies block. It will also generate a task called compileSpeedTestJava for you.

For an example, take a look at defining new source sets in the Java plugin documentation

In general it seems that you have some incorrect assumptions about how dependency management works with Gradle. I would echo the advice of the others to read the 'Dependency Management' chapters of the user guide again :)


You should try this one :

task getDeps(type: Copy) {
    from configurations.runtime
    into 'runtime/'
}

I was was looking for it some time ago when working on a project in which we had to download all dependencies into current working directory at some point in our provisioning script. I guess you're trying to achieve something similar.


I have found this answer https://stackoverflow.com/a/47107135/3067148 also very helpful:

gradle dependencies will list the dependencies and download them as a side-effect.


For Intellij go to View > Tool Windows > Gradle > Refresh All Projects (the blue circular arrows at the top of the Gradle window. enter image description here


A slightly lighter task that doesn't unnecessarily copy files to a dir:

task downloadDependencies(type: Exec) {
    configurations.testRuntime.files
    commandLine 'echo', 'Downloaded all dependencies'
}

Updated for kotlin & gradle 6.2.0, with buildscript dependency resolution added:

fun Configuration.isDeprecated() = this is DeprecatableConfiguration && resolutionAlternatives != null

fun ConfigurationContainer.resolveAll() = this
  .filter { it.isCanBeResolved && !it.isDeprecated() }
  .forEach { it.resolve() }

tasks.register("downloadDependencies") {
  doLast {
    configurations.resolveAll()
    buildscript.configurations.resolveAll()
  }
}

Downloading java dependencies is possible, if you actually really need to download them into a folder.

Example:

apply plugin: 'java'

dependencies {
  runtime group: 'com.netflix.exhibitor', name: 'exhibitor-standalone', version: '1.5.2'
  runtime group: 'org.apache.zookeeper',  name: 'zookeeper', version: '3.4.6'
}

repositories { mavenCentral() }

task getDeps(type: Copy) {
  from sourceSets.main.runtimeClasspath
  into 'runtime/'
}

Download the dependencies (and their dependencies) into the folder runtime when you execute gradle getDeps.